Cytology is the branch of biology dealing with the study of the formation, structure, and function of cells. As applied in a laboratory setting, cytologists, cytotechnologists, and other medical professionals make medical diagnoses of a patient's condition based on visual examination of a specimen of the patient's cells. A typical cytological technique is a “Pap smear” test, in which cells are scraped from a woman's cervix and analyzed in order to detect the presence of abnormal cells, a precursor to the onset of cervical cancer. Cytological techniques are also used to detect abnormal cells and disease in other parts of the human body.
Cytological techniques are widely employed, because collection of cell samples for analysis is generally less invasive than traditional surgical pathological procedures such as biopsies, whereby a tissue specimen is excised from the patient using specialized biopsy needles having spring loaded translatable stylets, fixed cannulae, and the like. Cell samples may be obtained from the patient by a variety of techniques including, for example, by scraping or swabbing an area, or by using a needle to aspirate body fluids from the chest cavity, bladder, spinal canal, or other appropriate area. The cell samples are placed in solution and subsequently collected and transferred to a glass slide for viewing under magnification. Fixative and staining solutions are typically applied to the cells on the glass slide, often called a cell smear, for facilitating examination and for preserving the specimen for archival purposes.
In a laboratory, for example a cytology laboratory, a cytotechnologist examines numerous specimen slides under a microscope in order to analyze certain specimen cells of questionable nature. When such suspect cells are located, the cytotechnologist generally marks the slide at that point, so that he or she may recall the location of the cells at some later time for further examination. To date, cytotechnologists have marked slides generally by using one of several manual methods.
One such method exists where a cytotechnologist marks the area of the microscope slide in question with a marking pen. To accomplish this, the cytotechnologist must take his or her eyes away from the eyepieces of the microscope, position the pen tip in the field of view, return his or her eyes to the eyepieces of the microscope, and then manually mark the slide with the pen while viewing the slide under magnification through the eyepieces. This task is difficult in great part because of the sizes of typical objects of interest, about 50 to 100 microns, and typical fields of view, a few millimeters in diameter, and requires fine motor control and good eye-to-hand coordination. Further, this task requires the cytotechnologist to refocus his or her eyes, move his or her body into a potentially awkward position in order to place the pen tip at an area to be marked on the slide, and to make a guess as to the placement of the mark. Moreover, this method of slide marking can be time consuming and is typically not very accurate.
The cytotechnologist may also mark the area of interest with a marking pen while the slide is under microscopic review. To accomplish this, the cytotechnologist must steer the pen at an angle into a small field of view. This task is difficult because of the relative sizes of the pen tip, about 1 mm, and the field of view, which may be as small as about 2.2 mm in diameter with a 10× magnification objective lens. Once the pen is in the field of view, the cytotechnologist must attempt to draw a dot, an arc, or an “L” shape, which are conventionally used to mark areas of interest. Standard microscope configurations do not lend themselves to this marking method.
Another such method consists of marking a microscope slide by using an objective-like configuration marker. In this method, the cytotechnologist must take her eyes away from the microscope eyepiece, rotate the microscope nosepiece until the marking apparatus is in place, and then manually push the marking apparatus down onto the slide in order to mark the area in question. This method requires the cytotechnologist to refocus her eyes and to move her body into a potentially awkward position. Although this method is more accurate than the previously described method, it is still tedious and time consuming. Further, improperly rotating the microscope nosepiece may lead to errors in marking.
The Olympus' “U-Marker” marking apparatus is mounted to an objective lens. Once the cytotechnologist identifies an object of interest, he or she actuates a pen included in the marking apparatus onto the slide to make a mark using the U-Marker. Because the cytotechnologist cannot see through the microscope while the mark is made, they are marking blindly. Also, if the cytotechnologist marks the slide while looking through the microscope, they can only mark with a dot. Further, because the pen is actuated toward the slide at an angle, using the U-Marker has limited accuracy. Moreover, the mount of this method requires the use of custom pens, limiting the cytotechnologist's choice of marking instruments. In addition, the pen is connected to the marking apparatus in such a way as to preclude capping of the pen, which leads to evaporation of ink when the pen is not in use.